Ok guys I need help with this.
Am running a 48 Ida on a 12A I was wondering what jeting should I run to make the car run properly???Or is ths carb to big for a stock 12A?.
Eventually am running 160 air ,190 main with 38 venturis but it chokes when I take off.I think i need to down size or???
Also will run K&N filter and RB Headers.

Thanks

 

if you were gonna stay stock, then i wouldnt run a webber 48 IDA on it. just modify the nikki

 

The IDA is to big so plan on running rich. Maybe wacky or someone that knowss more about these carbs can help.

 

Keep the weber since you already have it all set up. The 38mm chokes are your problem. A stock 12A would need about 30's(thats just a guess since I've never had a weber on a stock engine) Those 38's would be fine if you never got below about 4000rpm. Your losing vacuum signal at low rpm with the huge venturis which makes the carb not pull enough fuel. Jetting those 30's (or whatever you end up with) the old rule is venturi x4 for mains, that number plus 50 for airs. If racing or going for power go a little higher on mains and lower on airs(so plus 30 or 40)

 

Well I only have this Carb so i have to make it work for right now till I finish my street port 13b.I had a friend that run the 48 IDA on stock 12A and run really nice but I can't fine him anywere to ask on set up.
Now I can run a 45 dcoe weber side draft but what jets on this one???
And the nikki don't have one and not planing to look for one either.

I know is a big carb for the 12A but I seen it done and run very nice I just can't fine the right set up to stop it from choking.
I need the car running with what I have till the little moster 13B is done.

 

You should be able to get your 48 IDA to run pretty good. Have you checked your plugs after driving around? I think you need to play with your jettings some and down size them alittle. Venturi size is ok. Your exhaust is still stock? What size is your needle valve? Fuel pressure? Need more info.

 

Right now I have the stock headers but will be change next week with the RB header and also install a MSD box and FC coils and buy new spark plugs.
Also I think that by using the stock fuel pump is not delivering enough fuel to the carb but I can be wrong too. I was thinking on installing a red Holley or carter since is cheaper.
And the size of needle valve?, I have no Idea what it is Ill find Out.what is recommended?

 

You need to run a constant 4.5 psi to the carb. A Holley or Carter fuel pump will still require you to run a fuel pressure regulator. Right fuel pressure is important. You should be running atleast a 250 needle valve.

 

Ok so far I have 250 needle valve, 38 venturi But what about the main jets and air jets??? I don't have that many numbers to play with so I need more help before I go and spend some money in jets.
Thank you

 

Junk the 38 venturies and run 40 at a minimum. air jet 150 and start with 190 main. idle jet 65+. Junk the fuel filter under the large banjo bolt (fuel inlet) and drill out the funnel looking inlet. This will ensure that you dont starve for gas even at 4psi. IIRC 0 by-pass jet at the bottom of fuel bowl.

250 n/s. 300 n/s or glass needle/seat is what I prefer.

 

Master IDA speaks! wondering when you were going to respond. I actually thought you were going to tell him to junk it and sell it to you. lol

 

welps, he's got a bad reputation mang

 

Wow that's the answer I wanted Ill try all that and then let you guys know if I still want to suicide
Thank you

 

Thank's wackyracer I did everything u said and now it runs perfectly smooth and nice I can finally drive the car and not worry about it.
I end up using 195 on main jets 155 on air and 300 n/v and 40 venturis.drill the inlet and toss the filter. am happy.

Know I can take my time and build my street port 13b and then ask for help again.
Thank you all.

 

I have a stock 12a also with a 48ida. Stock header, straight piped. going to get rb header soon. I currently have 135- main
120-air
37mm Venturies
200 N/v
Idle-70 f10 emulsion tubes. So if I run what you got it'll run nice? This things a pain to tune. - thnks denton

 

How has this setup ran for you all these years?

 

Last activity was 10 years ago and the post was a bit confused/contradictory...

 

Agreed Peejay. From reading all the forums, it seems like the stock Nikki is the way to go on a stock 12a. My carb is in bigtime need of a rebuild so I wanted to see if upgrading to a Weber or Holly is worth it for my stock setup.

 

you COULD do a Weber on a stock 12A, but it would take a while to get it all jetted, plus it gets expensive.
it seems like the Nikki would be the better choice.

 

A local to me runs 51mm IDA's on a stock 12A with aftermarket headers and stock exhaust. He asked me to tune the carb for him. I told him to run a Nikki. I also told him to ditch the points ignition, and go electric.

I didn't touch it and he went to a "better mechanic" to tune his carb.

So many people don't understand what CFM means.

 

Agreed guys, it's pretty much one expense after another going with the weber setup.

 

A stock 12A can run a weber fine, size the chokes appropriately and go from there.